Water heating device



O United States Patent [111 3,546,429

[72] Inventors Ralph C Fleet [56] References Cited Briflm" UNITED STATESPATENTS agg gtl fig gf 'zf 2,375,871 5/1945 Reifenberg 219/316 4 211App] 816,623 2,80 ,534 8/1957 Coates 219/316)( [22] Filed April 16, 1969Primary Examiner-J. V. Truhe [45] Patented Dec. 8, 1970 AssistantExaminer-C. L. Albritton [73] Assignee Phydrex Limit d Attorney-RaymondA. Robic Quebec-Quest, Quebec, Canada [54] WATER HEATING DEVICE 4Claims, 8 Drawing Figs.

[52] US. Cl. 219/312,

. 2l9/3l6,219/3l8 [5 1] Int. Cl. F24h 1/18 [50] Field of Search 219/306,

ABSTRACT: A water heating device comprising a closed tank, a heatingelement attached to the vertical wall of the tank and projectinginwardly into the tank, a hood also attached to the wall of the tank andoverlying said heating element in spaced relation thereto, the underside of the hood being open for free circulation of water around theheating element, and a discharge tube connected to the hood andterminating at a point adjacent to the top of the tank for dischargingthe water heated by the heating element directly into the upper portionof the tank.

PATENIEBUEE 81976 3546429 sum 1 OF 2 III I II I IIIIIIIII INVENTORSRalph Gregoire FLEET Charles deJERSEY PHILLIPS Stuart H. FLEE ATTORNEYPATENTED .UEE 8197B INVENTORS Ralph Gregoire FLEET Chcries deJERSEYPHILLIPS Stuart H. FLEET WATER HEATING DEVICE This invention relates toa water heating device and more particularly to a hot water circulatorfor use in water tanks providing hot water for domestic use.

Domestic water heaters have been used for years and generally comprise aclosed tank connected to a cold water inlet, a heating element disposedin the tank for heating the water contained in the tank, and a hot wateroutlet supplying hot water to various household appliances. Waterheaters have been improved over the years and some of them are equippedwith means for providing an almost instantaneous supply of hot water.U.S. Pat. No. 2,784,291 issued Mar. 8, 1957, for example, discloses awater heating device wherein the heating element is contained in ahousing having a number of holes therein to allow cold water to enterthe housing. Such housing is connected to a tube adapted to dischargethe water being heated in the housing directly into the hot waterdischarge outlet of the tank.-

In the above prior art devices, steam pockets are developed in thehousing surrounding the heating elements due to the process of quicklyheating water in a too restricted area. Such steam pockets rise to thetop of the tank through the above mentioned tube and flow in the hotwater discharge line thus causing severe line and boiler knocks anddanger of steam burns to the hot water users.

In the above-mentioned U.S. Pat. No. 2,784,291, the tube which extendsupwardly from the housing containing the heating element terminates in abell-shaped hood which is connected directly to the hot water dischargeoutlet. Such hood restricts the circulation of hot water in the tank andprevents filling the complete top portion'of the tank with heated water.

The above-mentioned drawbacks are overcome, in accordance with theinvention, by using a hood which surrounds the upper portion of theheating element only instead of a housing enclosing the heating elementon all sides. The use of an open hood eliminates the pressure buildup ofthe heated water around the heating element which causes the formationof the above mentioned steam pockets and, in addition, allows the excesshot water that has not risen through the discharge tube to expanddownwards through the open portion of the hood under tit" heatingelement. Such downwards circulation of heated water from around theheating element and from under the hood preheats the cold water enteringthe tank through the cold water inlet which is located at a point belowthe heating element.

A second feature of the invention resides in that the discharge tubewhich rises'up to the top of the tank terminates a given distance fromthe top of the tank. Consequently, the flow of hot water in the tube isin no way restricted by any direct connection to the hot water dischargeoutlet and allows the complete top portion of the tank to be filled withheated water which is permitted to circulate freely in the top portionofthe tank.

The invention will now be disclosed more fully with reference to thefollowing drawings which illustrate a preferred embodiment of theinvention and in which:

FIG. 1 illustrates a vertical-sectional view upon a plane passingthrough the longitudinal center line of a water tank equipped with aheating device in accordance with the invention;

FIG. 2 is an enlarged section view of a portion of the heating deviceillustrated in FIG. 1;

FIGS. 3 and 4 are perspective exploded views of the heating device;

FIGS. 5 and 6 illustrate alternative aligning members for maintainingthe top portion of the tube in position in the tank;

FIG. 7 illustrates a section view taken along line 7-7 of FIG. 1; and

FIG. 8 illustrates a section taken along lines 8-8 of FIG. 1.

Referring to FIG. 1 of the drawings, there is illustrated generally acylindrical tank 10 having a vertical wall 11, a dome top 12 and aconcave bottom 13, although other configurations are obviouslyenvisaged. Mounted on the lower portion of vertical wall 11 is a heatingdevice designated generally by reference numeral 14 and including aheating element 15 and a hood 16 overlying the heating element in spacerelation thereto. The under side of hood 16 is open while a tube 17rises from the top of the hood toward the top of the tank. Tube 17terminates a predetermined distance from the top of the tank and isalined with a discharge outlet 18 located at the top of the tank.Aligning fingers 19 which will be disclosed more fully in a later partof the description are provided for holding the end oftube 17.

The water heating device is illustrated more clearly in FIGS. 2 to 4 ofthe drawings wherein the elements corresponding to those of FIG. I areidentifiedby the same reference numerals. In addition, there is shown aflange 20 of U-shaped cross section, one leg of which is welded to thevertical wall 11 of the tank and the other leg of which. is providedwith four slots 21 adapted to receive bolts 22. Hood 16 has a flange 23at one end thereof and such flange has holes therein which are alinedwith slots 21 of flange 20 for receiving bolts 22. Heating element 15 issupported by a flange 24 also having holes therein noted that, in caseof failure,the heating element 15 may be removed from the tank withouthaving to remove the hood l6. Hood 16 is preferably made of stainlesssteel to insure long life but, obviously, other suitable materials couldbe used.

Heating element 15 is of the conventional type and comprises, as it maybe seen in FIGS. 7 and 8, resistance type heating wires 30 positionedtherein and insulated therefrom by insulating material 31. The terminalends of the heating wires 30 are connected to a suitable electricalpower supply by leads 32 and 33 as illustrated in FIG. 4. v

The use of a hood 16 instead of the conventional housing around theheating element 15 allows the capture of the water heated by heatingelement 15 andpermits such heated water to rise up to the top of thetank through tube 17. Because hood 16 is open at the bottom, there is nopressure built up around heating element 15 which caused thenondesirable steam pockets encountered in the prior art devices. Theexcess hot water that has not risen through the tube 17 expandsdownwardly through the open portion of the hood and preheats the coldwater entering the tank at inlet 34 in the vertical wall of the tank.

As mentioned previously, the tube 17 rising from the top of the hood l6terminates a downwards distance from the top of the tank and isunobstructed in any way so that the heated water from around the heatingelement 15 and from under the hood 16 is freely allowed to circulateupward through the tube 17, then outward following the contour of thetop of the tank, then downward parallel to the vertical walls of thetank in diminishing velocity as it turns inward toward the tube 17 andthen rises slowly to join in repeated cycles with the hot water on topof the tank, thus causing an intense circulation of hot water buildingdownwards progressively from the top of the tank. The reverse of theabove described circulation occurs in the water at the level below thehood as mentioned previously. The two combined circulations cause themaximum of heated water to be immediately delivered to the top of thetank filling first and immediately the portion of the tank between theupper end of tube 17 and the top of the tank giving an immediate supplyof hot water at the outlet 18 of the tank.

The above mentioned circulation continues as long as the heating elementis energized by a suitable power supply through a thermostat (notshown), usually located adjacent to the bottom of the tank, until theupper and lower circulations have completely heated the water to apredetermined temperature. When such temperature of the water isreached, the above-mentioned thermostat cuts off the electric current tothe heating element as it is known in the art.

When hot water is drawn from the outlet 18 at the top ofthe tank, anequivalent amount of cold water enters at the bottom of the tank throughcold water inlet 34. The change in the temperature immediately activatesthe thermostat which causes the heating element to heat the cold waterand to immediately replace the amount of hot water drawn off from thetop of the tank with an equal amount of heated water from under the hood16 around heating element 15.

In FIG. 1 was illustrated a pair of aligning fingers 19 for maintainingtube 17 in alignment with discharge outlet 18. Such aligning fingers arealso used to assist in the installation, orientation and removal of tube17 through the discharge outlet l8. Aligning fingers 19 protrude throughthe entry of discharge outlet 18 and spring tightly against the sides ofoutlet 18 to keep tube 17 in position. Of course, such aligning fingersmay take other configurations and may even be integral with the tube 17such as illustrated in FIGS. 5 and 6.

" As illustratedperhaps more clearly in FIGS. 7 and 8, tube 17 isscrewed into the top portion of hood 14. Such is done by means of anysuitable tool through the outlet 18 after the heating device has beeninserted into the tank and attached to the vertical wall of the tank.

The hood 16 is also provided with holes 35 in the top portion thereof toallow escape of small steam pockets which, despite the novel hoodarrangement, could get trapped under the hood as illustrated in FIGS. 2,3, 4 and 8. Holes 35 may be of various diameters and may vary in number.Their location in the surface of the hood may also vary.

Considerable savings can be realized by using a hood instead of theconventional housing as the former can be made of relatively light andsimple stampings with no machining required while the latter requires arelatively heavy casting or assembled series of parts requiringconsiderable machining.

High savings in maintenance and repairs can also be realized by the useof a hood instead of the conventional housing because, in the case ofthe former, the heating element remains relatively scale free owing tothe fact that the heating element is covered by the hood and completelyopen on the underside thereof. Furthermore, the heating element may beremoved for replacement and for cleaning without disturbing the hood,while in the case of the conventional housing surrounding the heatingelement, it is obvious that in a short time the element will becomecompletely enveloped in scale neces sitating the complete removal andreplacement of the heating element and housing.

I claim:

1. A water heating device comprising:

a. a closed tank;

b. a heating element attached to the vertical wall of the tank andprojecting inwardly into the tank;

c. a hood also attached to the vertical wall of the tank and overlyingsaid heating element in spaced relation thereto,

the underside of said hood being open for free circulation of wateraround the heating element, holes being provided in the top of said hoodto allow escape of small steam pockets which are formed around theheating elements during the heating process and become trapped under thehood; and

d. a discharged tube connected to the hood and terminating at a pointadjacent to the top of the tank for discharging the water heated by theheating element directly into the upper portion of the tank.

2. A water heating device comprising:

a. a closed tank;

b. a heating element attached to the vertical wall of the tank andprojecting inwardly into the tank;

c. a hood also attached to the vertical wall of the tank and overlyingsaid heating element in spaced relation thereto, the underside of saidhood being open for free circulation of water around the heatingelement;

d. a hot water discharge outlet located in the top of the tank;

and a discharge tube connected to the hood and terminating at a pointadjacent to the top of the tank for discharging the water heated by theheating element directly into the upper portion of the tank, saiddischarge tube having aligning fingers secured to the upper end thereofand projectoverlying said heating element in spaced relation thereto,

the underside of said hood being opened for free circulation of wateraround the heating element;

d. said hood and heating element being attached to the vertical wall ofthe tank by means of a flange having a U- shaped cross section, one legof said U-shaped flange being welded to the vertical wall of the tankand the other leg of said U-shaped flange having slots therein adaptedto receive bolts for holding said hood and said heating element; and

e. a discharge tube connected to the hood and terminating at a pointadjacent to the top of the tank for discharging the water heated by theheating element directly into the upper portion of the tank.

4. A water heating element as defined in claim 3, wherein said hood andsaid heating element each have a flange at their end which is locatedoutside the vertical wall of the tank, said last-mentioned flangeshaving holes therein corresponding to the slots in said U-shaped flangeand through which said bolts protrude to secure the hood and the heatingelement to said U-shaped flange.

